Lecture 3 Neuroimaging Techniques 1 Flashcards
What does CT stand for?
Computed Tomography
Describe how a CT works.
Based on X-Rays. The depth of the rays shows how dense the tissue is. X-Ray beam is put into a circular gantry and then spin the X-Ray around so enough information can be gathered to see internal structures past bone.
Why does bone appear bright and air appear dark on a CT scan?
Bone blocks the greatest number of X-Rays giving it a bright appearance. Air blocks no X-Rays so gives a dark appearance.
What does MRI stand for?
Magnetic resonance imaging
Describe how an MRI works.
Interested in the nucleus of hydrogen atoms. Radio signals absorbed by the hydrogen protons and a magnetic resonance signal is omitted.
What is a T1 weighted scan?
Characterised by CSF being dark and showing the contrast between white and grey matter.
What is a T2 weighted scan?
Shows liquid structures being very bright.